The present invention relates to test equipment for testing a power train (such as a transmission or a transaxle) of a vehicle.
FIG. 6 shows a first conventional test system having a mounting stand 2 supporting a test unit (a transaxle) 1 to be tested, a torque meter 3 connected with the input side of the test unit 1, a gear mechanism 4 equipped with a lubricating system and connected with the torque member 3, a drive motor 5 connected with the gear mechanism 4, two torque meters 7 connected, respectively, with two output shafts of the test unit 1, a pair of gear mechanisms connected, respectively, with the torque meters 7, a pair of lubricating units for lubricating the gear mechanisms 8, a shaft 10 for connecting the gear mechanisms 8 so that the speeds of both gear mechanisms arc held equal to each other, and a dynamometer (generator) 11 connected with one of the gear mechanisms 8.
In this test system, the test unit 1 is driven by the drive motor 5 through the gear mechanism 4 and the torque meter 3. The rotation of the test unit 1 is transmitted through the output shafts 6 to the gear mechanisms 8 rotating at an equal speed, and the dynamometer 11 absorbs the mechanical power. In this way, the torque and rotational speed arc measured and controlled.
FIGS. 7A and 7B show a second conventional test system which has a drive motor 5 connected, through a torque meter 3 and a connecting shaft 12, with the input side of a test unit 1 to be tested, a right gear mechanism 8 connected through a torque meters 7 with a right output shaft 6 of the test unit 1, a left gear mechanism 8 connected with a left output shaft 6 of the test unit, a connecting shaft 10 connecting the left and right gear mechanisms 8, and a dynamometer 11 connected through a connecting shaft 17 with the left gear mechanism 8. This test system is operated in the same manner as the first conventional system shown in FIG. 6.
FIGS. 8A and 8B show a third conventional test system in which the input shaft of a test unit 1 is connected through a torque meter 3 and a speed change mechanism 13 with a drive motor 5, and the left and right output shafts 6 of the test unit 1 are connected with left and right dynamometers 11, respectively.
FIG. 9 shows a fourth conventional test system in which a test unit 1 is attached to one of left and right mounting stands 2, and rotation of a drive motor 5 is supplied to the test unit 1 from the left or right side. A right torque meter 7 and a right gear mechanism 8 are mounted on a right movable bed 14, and a left torque meter 7, a left gear mechanism 8 and a dynamometer 11 are mounted on a left movable bed 15. The beds 14 and 15 are movable left and right as shown in arrows in FIG. 9. Therefore, the left and right output shafts 6 of the test unit 1 can be connected, respectively, with the left and right gear mechanism 8 through the torque meters 7 whether the test unit 1 is attached to the left stand 2 or the right stand 2. The drive motor 5 can be connected in a different direction as shown in a two dot chain line in FIG. 9.
FIG. 10 shows a fifth conventional test system. This system also has left and right mounting stands 2, but left and right torque meters 7, left and right gear mechanisms 8 and a dynamometer 11 are all fixed. There is provided a connecting shaft 16 for allowing connection between the left and right output shafts 6 of a test unit and the left and right torque meters 7 both when the test unit is attached to the left stand 2 and when the test unit 1 is attached to the right stand 2.
FIG. 11 shows a sixth conventional test system which can test power trains of both a right side engine driven type having an input member on the right side and a left side engine driven type having an input member on the left side. This test system includes a single drive motor 5 on the input side of the test unit, and two right-side gear units 8 connected, respectively, through two connecting shafts 10 with a left-side gear unit 8.
FIG. 12 shows a seventh conventional test system applicable to the right side engine driven type and the left side engine driven type. This system has two drive motors 5 and two torque meters 3 on the input side of the test unit.
In the first, second and third conventional systems shown in FIGS. 6, 7 and 8, it is necessary to change the positions of the drive motor 5, the gear mechanisms 8 and the dynamometer 11 in order to test power trains of both right side driven type and left side driven type, and accordingly, a large space is required. Moreover, the long connecting shaft 10 increases the inertia (or the moment of inertia), and the angle of the output shafts 6 is increased, so that these systems are not adequate for high speed testing. In the case of the fourth conventional system shown in FIG. 9 having the structure of the movable beds 14 and 15, the angle of the output shafts 6 is increased so that the high speed testing is difficult, a large space is required, and an aligning operation of the movable beds 14 and 15 is troublesome.
In the fifth system shown in FIG. 10, the left and right gear units 8 are widely spaced, so that this system requires a wide space and the long connecting shaft 10. Beside, the operation for moving the shaft 16 is troublesome. In the sixth conventional system shown in FIG. 11, the two right-side gear units 8 requires a wide space and increases the mechanical loss and the inertia. The seventh system shown in FIG. 12 requires the two drive motors 5, and the large gear units 8.